Regulation of lithospermic acid B and shikonin production in Lithospermum erythrorhizon cell suspension cultures

Cell suspension cultures of Lithospermum erythrorhizon produced a large amount of lithospermic acid B, a caffeic acid tetramer, as well as shikonin derivatives (each ca. 10% of dry, wt.) when cultured in shikonin production medium M-9. Various culture factors for increasing the production of lithospermic acid B were investigated. Lithospermic acid B production was inhibited by 2,4-D or NH4+, whereas it was stimulated by Cu2+, These regulatory patterns were similar to those for the production of shikonin derivatives in these cell cultures, suggestive of close relations and similar metabolic regulation between the production of these compounds. Cultivation under light illumination, however, showed that these metabolisms were independently regulated. In particular, blue inlight showed a stimulatory effect on lithospermic acid B production, while shikonin production was strongby hibited, indicative of an effective condition for lithospermic acid B production.